﻿/*
* Copyright (c) 2014 Microsoft Mobile
* 
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
* 
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
* THE SOFTWARE.
*/
using System;
using System.Collections.Generic;
using System.Text;
using System.Windows.Input;

namespace Lumia.Imaging.EditShowcase.ViewModels
{
    public class DelegateCommand : DelegateCommand<object>
    {    
        public DelegateCommand(Action execute, Func<bool> canExecute)
            : base(_ => execute(), _ => canExecute())
        {
    
            if (execute == null)
                throw new ArgumentNullException("execute");

            if (canExecute == null)
                throw new ArgumentNullException("canExecute");
        }

        public DelegateCommand(Action execute)
            : this(execute, () => true)
        {
        }
    }

    public class DelegateCommand<T> : ICommand
    {
    
        private Action<T> execute;
        private Func<T, bool> canExecute;

        public event EventHandler CanExecuteChanged;

        public DelegateCommand(Action<T> execute, Func<T, bool> canExecute)
        {
        
            if (execute == null)
                throw new ArgumentNullException("execute");

            if (canExecute == null)
                throw new ArgumentNullException("canExecute");

        
            this.execute = execute;
            this.canExecute = canExecute;
        }

        public DelegateCommand(Action<T> execute)
            : this(execute, _ => true)
        {
        }

        public bool CanExecute(object parameter)
        {
            if (!(parameter is T) && parameter != (object)default(T))
                return false;

            return canExecute((T)parameter);
        }

        public void Execute(object parameter)
        {
            execute((T)parameter);
        }

        public void NotifyCanExecuteChanged()
        {
            EventHandler eventHandler = CanExecuteChanged;

            if (eventHandler != null)
                eventHandler(this, EventArgs.Empty);
        }
    }
}
